1. Technical Field
The present invention relates generally to handheld power tools. More particularly, the present invention relates to attachments and methods for use with reciprocating tools.
2. Background Art
Reciprocating tools known in the art generally provide a handheld tool body that houses a motor and a gear or cam transmission for translating rotary motion of the motor shaft into reciprocating linear motion. A reciprocating tool chuck is typically attached to the gear transmission or cam for securing a removable blade or other modular instrument to the tool. In some conventional applications a chisel or an edged tool such as a cutting instrument can be secured to the tool chuck. In other embodiments, a hammer or other blunt instrument can be attached to the tool chuck for driving nails or breaking up materials.
One problem associated with conventional reciprocating tools is the placement of the tool chuck near the centerline of the tool body. Generally, the tool chuck extends from the gear transmission or a reciprocating rod attached thereto along the centerline of the tool body. Such placement of the tool chuck creates a lateral offset between the outer right or left edge of the tool body and the corresponding instrument, i.e. blade, when installed on the tool chuck. A lateral offset between the edge of the tool and the attached instrument creates difficulty in using a conventional reciprocating tool to operate on a workpiece in a corner or in applications where a flush cut near a planar or curved surface is desired. Generally, in some applications, the offset between the tool chuck and the edge of the tool in conventional reciprocating tools makes it impossible for a user to position an attached instrument directly against or parallel to a surface for operating on an adjacent workpiece that that extends from or is positioned near the surface.
Others have attempted to solve the lateral offset problem associated with conventional reciprocating tools by providing an instrument for attachment to the tool chuck that has a bent or offset region. For example, U.S. Pat. No. 6,871,405 provides a reciprocating saw blade extension with a lateral offset. Similarly, U.S. Pat. No. 7,631,584 provides a tool adapter for use with a reciprocating saw. However, some previous attempts provide only an adapter that extends from the tool chuck. As such, some previous attempts to solve the lateral offset problem provide only one point of contact between the instrument and the reciprocating tool located at the tool chuck. Conventional offset configurations in some applications can create a bending moment about the tool chuck and can cause unstable forces acting upon the reciprocating tool and the instrument, i.e. blade, causing the instrument to bend or torque during use. This type of instability can result in potential blade failure or workpiece damage and can create an unsafe operating environment.
Additionally, in some applications it may be desirable to quickly and accurately cut one or more large sheets of material, for example sheet metal, plastic, composite material, cardboard, plastic, nylon, fabric, carpet, wire lath of the type used for stucco, wire mesh, etc. Such materials may be supplied in large rolls or in planar sheets. Conventional handheld power tools and corresponding methods for cutting large sheets of material generally include using rotating saw blades of the type found on handheld rotary power saws or reciprocating saws having a single blade. Such conventional handheld power tools have several disadvantages for cutting large sheets of material.
One problem associated with conventional handheld tools and methods for cutting sheets of material is the distance the tool protrudes through the material. For example, a large piece of sheet metal may be placed on a flat substrate such as a floor for cutting. Conventional power tools for cutting sheet metal generally protrude through the sheet, thereby interfering with and/or damaging the floor substrate upon which the metal sheet is positioned. Thus, conventional power tools and methods require a clearance on both sides of the material to be cut. Additionally, conventional handheld power tools for cutting sheets of materials can bend or warp the material at the cutting seam. Other manual handheld tools for cutting sheets of materials include manual shears, cutting scissors and snips, but such instruments are exceptionally slow for cutting large sheets.
Thus, improvements in handheld cutting tools and machinery of the type used for cutting materials are generally needed in the art. Also needed are methods associated with cutting materials using a reciprocating tool.